In-Plane Flexible Ring Tire Model Validation Through ADAMS FTire Model Virtual Tests

This paper presents the validation for the newly developed in-plane flexible ring tire model by using ADAMS FTire model simulation. The developed in-plane model is unique in two aspects: (1) the neighboring belt segments are connected through normal and tangential directions by springs and dampers, each belt segment is a rigid body and its mass is accumulated at its geometric center. Each belt segment is always perpendicular to the line formed by the wheel center and the belt geometric center, thus there is no rotational constrains between the neighboring belt segments; (2) the representation of the tangential friction force between the tire and the road is defined through the multiplication of the normal contact force and the friction coefficient. And the friction coefficient is obtained based on an empirical model of the tire slip. For validation, a quarter-car model first runs on a flat road with a constant velocity (40km/h) and then rides over a rectangular shape obstacle to identify the tire parameters based on the virtual tests of Gipser’s FTire model in ADAMS. Then the quarter-car model runs on a flat road with 4–5 different conditions to ride over each obstacle: rectangular shape, triangular shape, half circle, and trapezoid. Simulation results for the new in-plane flexible ring model are compared with virtual test results from ADAMS FTire model on the same road and velocity condition for the tire patch contact forces in horizontal and longitudinal directions respectively based on the SAE standard J2812. Note that this study is the first time that the new SAE standard J2812 is used for model validation. After the validation, two important aspects have been investigated: (1) What is the minimum height of each obstacle shape so that the parameter identification will have minimum equipment loads? (2) What should the minimum number of belt segments be for each obstacle shape? The above two aspects are useful for tire model end users and tire experimental experts in real world applications.